Congratulations on the nice clutch!
Yes, as Jorge mentioned, when the clutch is glued all together in a big pile the whole mass of eggs will act like a sponge and absorb moisture from the incubating medium into the outside eggs and into the next neighboring eggs, and so on. And also as he mentioned I keep a close eye on the higher eggs that are not touching the medium for any dimpling too. If they do start to dimple, I will check my hatching medium to see if it needs a tad more moisture, but if it seems okay, I will sometimes drape moist fluffed-up sphagnum moss over the top of them to help out.
Even if the moisture seems okay for the outer eggs that are contacting the medium, and I start to notice some dimpling in the inner or higher eggs, I will drape them as needed to retain a nice smooth look anyway. The less holes in the container, the less humidity will be lost. I probably allow them to airate a tad more than some folks, but I just want to make cetain that no carbon dioxide gasses build up over the eggs is all. That can sometimes kill embryos that near full-term. It could even cause certain defects too I would think if it didn't actually kill them.
Alot of people prepare the vermiculite/perlite mixture with too much water too. I like to very slowly add water so the stuff just clumps together some when you squeeze it with your fist. Too wet and the eggs will absorb so much moisture the eggs will swell and drown the embryo. It can also swell the egg so much it bulges out the eggs into weird shapes and even can rupture and leaks.
Good luck with the nice clutch!
~Doug
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"a snake in the grass is a GOOD thing" 
my website -Serpentine Specialties
